Rotary blower.



T. W. GREEN.

ROTARY BLOWER.

- APPLIOATION FILED 11.111. 24, 1911.

2 SHEETS-SHEET 1.

. A g y 6 Wai 1 l. I

,Wm 2 2J/ 47 y l 1 j@ '19 W 1@ 'l0/l INV Y ATTORNEY T. W. GREEN.

ROTARY BLOWER.

APPLIUATIQN FILED 111111.24, 1911.

1,004,776. Patented Oct. 3, 1911.

2 SHEETS-SHEET 2.

`MJIIIIIIIIIII f IIIEIIIIIEIE HHH I WITNESSES fTBoM-As'wf. GREEN,onrmrannniiia, PENNSYLVANIA.

ROTARY Btownn.

. Specication of ettersjlatent. i

f Patented. oct. 3,1911.

To all whom it may concemr -Be it known that I, THOMAS W. GREEN, a

citizen of the United States, and a resident of which thev following isa specification.

.of Philadelphia, vPennsylvania, have invent-` ed a certain new anduseful Rotary Blower,

My invention relates to blowers and particularly Ato that type orcharacter of blower in which two impellers alternate in position andcooperate to perform the locking or valve functions for each other.

One of the purposes of my invention is to provide plane faces for thelock or seal portions upon each impeller which cooperate with a blade oftheother, in order to Vsimplify themachining-ofthese' locks and toprovide for adjustment to maintain effective seals with the bladesnotwithstanding wear,

or variation in the relative angular positions connecting gearing orother parts.

A further purpose of my invention is to provide adjustment of the planelocking portions, preferably into parallel plane positions. .e 1

A further purpose of my invention is to provide reliable quick adjustingmeans for the plane surfaces involved and to make them capable 0f niceadjustment.

further purpose of my invention is to provide for adjustment of thesealing lock arngularly yvith respect to its length, which I prefer toaccomplish by making -the ends of the lock separately adjustable.

A further purpose of my. invention is to equip the ends of impellerblades with sealson ofl it.

lng members which are'made effective in proportion to the pressure usedand by rea- `Further-- purposes of my invention and i novel details ofconstruction will appear in the specification and claims hereof.

In the drawings I have selected for illustration an embodiment of myinvention whichis highly practical, eiicient and inexpensive, from amongthe many available forms.

Figures 1 and 2 are transverse vertical sections of the preferred formof my invention,

corresponding to the section at in Fig. 3, but with the impellers inslightly different positions. Fig. 3 is a horizontal section of myinvention corresponding to the section at w-Jw in Fig. 1. Figura@ is arelatively enlarged elevation of a part, of the structure Application.nledimarch v24,A 1.9:,12v seriauNo. 616,728.

the structure seen in Fig. 5. irelatively enlarged section of the outerend j o f one of the impellers of Figs. 1 and 2. Fig.

8 is a brokenelevation, showing a modificaytion of one part ofmyinvention. Fig. 9 is and outlet opening 5. these'openings is providedwith flanges 6 plate. '.Fig. 5 is a section corresponding to lineV.a-.z'of Fig. 4 but with the plate in place. Fig. 6' 1s a broken endelevation of Fig. 7 is a a broken section upon line y-y of Fig. 8.

The same reference numerals indicate like parts'l inthe drawings.

In the form illustrated, 1 designates a casyin 'or frame, here called acylinder, semicy indrical in cross section at the parts 2 and 3 andstraight between these parts.

Within this two cooperating impellers lare i placed. The casing isprovided with two openings for the gasor liquid which is being ofthe twoimpellers because of wear to the 'the outlet. Their character isdtrminedby the direction of rotation of the impellers.` With thedirection indicated `by the arrowsv pumped, one being the inlet and theother in the ligures, these become inlet opening4 AThe casing about bywhich suitable piping is attached andthe cylinderis flanged at its endsat 7 for attachment of cylinder heads 8 which carry the bearings 9l forthe shafts 10, 11-' upon which the two impellers are mounted. I providesuitable glands 12 for these bearings whenever gas is being pumped andthe pressure is sufficient to make leakage therethrough objectionable,and drive one of the impellers by the shaft of the other, in proper timerelation thereto, through two equal gears 13 which are held in place byset screws 14 passing through bosses 15 upon the gears. Upon one end ofone of the shafts, preferably that end opposite the gearing, I mount anysuitable pulley or other driving device 16; so that the bladesof oneimpeller 17 may be properly driven and timed to pass within the lwaist18 of the other impeller 19, and vice versa.

For the purpose of assisting in the sealing function between theimpellers and coperating parts when handling gases and light liquids,and of making the tightness of the seal correspond in large measure withthe 'need therefor by reason of the pressure used,

I may groove the impellers longitudinally at their outer extremitiesas.at 20, and insert therein' sealing.. material of any suitable l agearing, permits adjustment of any one.or

all of the plane faces to rovide for wear of V `quite satisfactory forthe purpose. The cylindrical shape of the sealing material is quitedesirable as it results in slight rotation thereof in use, whereasregular polyg- .onal shapes would require withdrawal and reinsertionwith the other sides successively exposed to approximate the samedistribution of wear about the surface of the sealing materialautomatically attained'by the 5 circular form. The outward pressure uponthe sealing material is made proportionate to the force tending to causethe air or other material to pass it.

The main aims of my invention, in so far as it relates to the sealingparts or faces of the waist of each impeller, are to secure ease andaccuracy in the machining of these parts and to make them adjustable. Iattain the rst aim by making these parts plane upon their surfaces andfurther simplify the construction, as well as the laying out of thisWork in the shop, by making the plane face upon one side of the impellerwhich forms part of the surface of one waist lie within the same planeas that face upon the other side of the impeller which forms a part ofthe opposite side of the other waist. I also make the other two planewaist surfaces cooperating respectively with the two above stated, asparts of another plane at right angles to the plane irst stated.

l The adjustability attains three advantages. It permits the two planesurfaces upon opposite sides of the same waist to be adjusted, oneoutwardly and' the other inwardly, to compensate for lag or lead of oneimpeller angularly with respect to the other because of wear of theconnecting the faces themselves or o the impellers, and, withindependent means'for adjusting the different ends ofthe planes, makesit possible to accommodate the plane faces to the impellers duringconstruction or erection when their faces are not strictly parallel,whether because of strain or whatever other reason. To secure thesebenefits, I

' form portions 23 of the locks or cut-offs of my impellers as planesurfaoes with which the outer, preferably belled, portions 24 of theblades cooperate. I have found the most desirable arrangement of theseto be that in which these planes are radial to limitingedges ofv theseplane surfaces with relation to the sealing `l1ne of the portions 24therewith at the tlme that the impeller ,begins to seal with another ofthe planel faces. I extend the plane surfaoes toward the center ofthe imeller sufficiently-to have a reasonable lap o these seals, both toinsure effective sealing of the one before the seal is released by theother and also to provide for variation of the exact lines at which bothseals become effective after wear' of the gearing and angular variationof the relative positions of the impellers take place. While I amproviding primarily in my adjustment for the wear in the gearing Withcorresponding relative angular variation in osition of the twoimpellers, and for cant- 1ng of the seals to bring' them intoparallelism with the cooperating impeller surface, it is evident thatwear of any character which might occur between the rotating parts canalso be provided for by the same adjustment.

While the exact vcurvature of the impeller blade could be determinedexperimentally, I prefer to determine the various centers of curvatureas follows: From the center of that part of the pitch circle 25 lyingWithin each blade as at 26, between the points 27 at which the pitchcircle cut-s the planes 23,

23', 232 and 233, I 'set ofi' points 28 upon a tangent 29 drawn tothe-pitch circle through 'the point 26. These points 27 and 28 are,

therefore, at a distance from 26 correspond- :ing to the chord ofone-eighth of the pitch gcircle. I then connect opposite points 27, V28as indicated. From the points 26 I next draw lines`26-3O which arechords of quarters of the pitch circle. The intersections of theselines-26-30 with the lines 27-28 at 31 and 32 give the centers aboutwhich I describe the portions 33 of the blade, using feach of thesecenters to describe the curve upon that face of the blade farthest fromsaid center. The connecting curves between portions 33 and the planesurfaces are drawn from centers 25 upon the pitch circle midway between26 and 27. Each center 25 is used for the curve upon the side of theimpeller nearer to it. curve forming the end of the impeller between thepoints 34 at which the curves 33 sodetermined leave the planecooperating surfaces of the seals 23, 23', etc., giving allowance forsuiiicient lap, may vary considerably and is laid out to cooperate withThe character ofthe the curvature of the parts of the waist of eachimpeller between the plane faces, so as to trap as little air aspossible therein and to give pro er waist width for the impeller shaftan reasonable impeller strength thereabout.

I have found that the method of designing l the curvesnof my impellerblades, as above defined, forms effective blade surfaces for coperationwith the plane sealing faces,

for the plane faces, corresponding differences in the impeller bladecurves will be required and these can be determined practiby means ofscrews 41,.

cally' with ease.

The planesurfaces of the locks `or cut-offs may be easily and accuratelylaid out and machined and are very desirable even when not adjustable.They may be made adjustable in any of a great variety o ways of which Ihave shown but two, one illustrating nicety and ease of adjustment andthe other simplicity of construction.

In the form shown in Figs. 5 and 6, I groove the impeller longitudinallyat 36 throughout its length, and with its depth' preferably tangentialto the pitch circle, to provide seats for plates 37, and cut itdeeper ateach edge to provide spaces 38 wit in which the operating lugs of wedges39 are placed. The plates 37 form the effective sealing faces,coperating with the. blades or vanes of the impeller's and are adjustedby means of the wedges 39, which may be 'moved independently, but whichare moved toward or away from each other to effect or permit outward orinward movement of the plates 37 through parallel positions. If the weartoward different-ends of the machine be different, or the machine be setup in a position to cause uneven stress or twist .upon the surfaces, thevariation can be taken up by adjusting one only of the wedges.

The movement of the plates 37 outwardly is here shownas limited by twosets of means, shown as screws, ofvwhich the set 40 at all times takesthe outward strain brought upon the plate bythe wedges 39 as these aredrawn toward each other by the screws 41. Before effecting additionaloutward movement of the plate 37, therefore, one or both of the screws40 must be slacked. to the desired extent, after which the wedge orwedges 39 are forced in to take up the slack Within the impeller body atthis point are cast or otherwise located sockets 42 whosel openings,best seen in Fig. 4, are of keyhole form, being enlarged at 43 to permitthe passagev of heads 44 of screws 45, while the openings are smaller at46 to retain heads 44 therein. The plates are inserted with the screws45 in place by passing the heads 44 through the openings 43. The platesare then moved longltudinally to position with the parts as shown inFig. 5, after which the wedges 39 are put 1n' place and the screws 40and 4l are inserted. f

rlfhe screws 45 are intended to limit the ultimate outward movement ofthe plates 37, particularly in 'case of withdrawal, accidentally orotherwise, of the screws 40. Both sets of screws 40 and 45 are intendedto protect against outward-strainsI but bothv are protected againststrains due to centrifugal forces by the engagement of plates 37 .withlthe edges 47 of the openings 36 in the lmpellers. Since the plates lie,preferably,

with their faces in radial position with respect to the impeller shaft,the centrifugal strains will be received squarely upon the preferablytangential edges 47 of the impeller and there will be no shearing norother centrifugal strains upon any of the screws or fastenings used. Thewedges 3S) are recessed at 39 to allow adjustment without interferencewith the screws 40.

In the form shown in Figs. 8 and 9 the same grooves 36 are used toprovide seating for the adjustable faces, and the same edges 47 receivethe radial thrust due to any centrifugal action present. The plate 37 isrctained finally by the dovetailed part 48 fitting in t-he correspondinggroove 49 and permitting insertion of this member from the end. Hereliners of different thickness or successively changed number areintended to be Ainserted at 50 and the plate is drawn back rigidlyagainst them by means of screws 5l passing through the material of theimpeller.

It will be evident that other forms of adjustment than by wedges orliners, and other securing and operating means than by screws, may beused and that a similar action might be obtained by movement of theplane surfaces in other directions than that indicated to effect theadjustment. lVhatever form of adjustment is used, all ofthe faces are,preferably, initially set at an intermediate position in their range ofadjustment. Vhen wear of the gearing requires adjustment, one of the twofaces upon thc same side of the impeller is set farther out and theother farther back in the impeller to bring the faces into operativerelation to the blade of the other impeller, whether it be lagging orleading. fear upon' the lock faces may also be compensated by outwardadjustment of the face which' is worn. Some of the advantages of theplane face may be peller, with interchange of these sealing functionssuccessively by the-waist and blade of the two impellers alternately andso as to maintain a continuous seal between the impellers at all times.In each sealing cooperation of one side of the waist of one impellerwith the blade of the other, the blade coperates with two sealing waistfaces, each of which faces in coperation witha blade presents anembodiment of one part of my invention. The plane faces, whetheradjustable or not, perform valve functions only in these relations, andare capable of uses where the rotor upon which they are mounted is avalve only, and never an impeller. I have, therefore, considered the onemember as an impeller and the other as a'valve only,

'in some of the claims.

Having thus described'my invention what I claim as new and desire tosecure by Let.

ters Patent is 1. In a blower, a pair of impellers, each having bladeand lock portions, the blade of one coperating with the lock of theother, and plane lock portions upon each impeller.

2. In a blower, a pair of impellers having belled blade` portions andplane facings for lock portions, the blade portions of each impellercoperating with the lock portions of the other.

' 3. In a blower, a pair of impellers having their blades belled andtheir lock portions lying substantially in planes radial.

4. In a blower, an impeller having belled blades in combination with arotary .mem-

` ber locking with the blades and havingv its locking surfaces plane.

5. In a blower, an impeller having belled blades in combination with arotary locking member, a movable facing coperating therewith and meansfor substantially tangentially adjusting the facing.

6. In a blower, an impeller having blades in combination with a rotarylockin member therefor, providing separate loc faces adjusting thelocking facestangentially with respect to the rotary locking member.

9. In a blower, an impeller having belled blades in combination with arotary locking 'clement having its locking faces lying substantiallywithin quadrant planes through the axis of its rotation.

10. In a blower, an impeller blade, a rotary sealing member therefor, anadjustable locking plate for the member` and separate adjustments fordifferent ends of-the lock.

11. In a blower, a pair of belled impellers, each impeller havingbelledblades on opposite ends and a lock on each side between the blades forone of the blades of the other impeller and having plane faces uponopposite sides of each lock.

12. In a blower, two cooperating impellers, each having two belledblades and intermediate plane sided locks.

13. In a blower, a belled blade having one side plane and approximatelyradial in proximity to the waist for engagement with another impeller.

. 14. In a blower, an impeller blade, a rotary sealing member therefor,a movable sealing face for the sealing member, longitudinally movablewedges for moving said face, means for moving the wedges/ and means forlimiting the movement of the sealing face.

15. In a blower, an impeller, a rotary sealing member thereforffamovable seal upon said member, wedges for moving said seal, means forlimiting the movement of the seal and additional means for limiting theultimate movement of the seal.

16. In a blower, an impeller, a rotary member coperating therewith and,longitndinally grooved to provide a substantia 1y tangential abutment, aremovable locking face -for the impeller located in said groove andresting agalnst the abutment and means for adjustlng the vposition ofsaid face in a tangential dlrection.

17. In a blower, an impeller blade, a rotar grobved to form a seatfor alocklng facing, a facing therefor, means admittln saidfacing bylongitudinal movement an ligniting the outward movement thereof andmeans for adjusting the facing. a

- THOMAS W. GREEN.

Witnesses:

THoisrAs D. MowLDs,

HELEN I. KAUFFMAN.

locking member therefor longitudinally-

